Venetian type blinds have a series of slats hung on ladders that extend from a headrail to a bottomrail. In most venetian blinds a pair of lift cords is provided each having one end attached to the bottomrail and then passing through elongated holes in the slats up to and through the headrail. Alternatively, the lift cords may pass through slots in the edges of the slats as shown in U.S. Pat. No. 5,573,051. A cord lock is usually provided in the headrail through which the lift cords pass. The cord lock allows the user to maintain the blind in any desired position from fully raised to fully lowered.
The slats rest on rungs between rails of the ladders. In most venetian type blinds the upper end of each ladder is attached to a drum. There is one drum for each ladder and the drums are carried on an axle. The blind is in an open position when the rungs are horizontal. To close the blind one operates a tilt mechanism that turns the axle to rotate the drums. This raises one rail of each ladder while allowing the other to be lowered thereby tilting the slats. Tilt mechanisms can be a wand type or a cord type. A wand tilter has a gear drive between the wand and the axle. Wand tilters are usually attached through a gearbox to one end of the axle. The drum of a cord tilter can be anywhere on the axle, but is usually at one end.
The window covering industry has been offering lines of stock blinds that come in standard widths. These blinds are sold through home centers and other large retailers who sell home furnishings. Should the customer have windows that have a width different from the standard width the retailer can trim portions off the ends of the headrail, slats and bottomrail of a standard or stock blind to create a venetian blind that fits the window. The amount that can be removed from a blind is limited to the distance between the outermost ladder and the edge of the blind (usually 6" or 152 mm) less the space required for the cord lock or tilt mechanism and a portion of the drum and cradle. This space usually requires about 3" to 3 1/2" (76 to 89 mm) depending if the lift cord and tilter are on the same side or opposite sides of the blind. Since the blinds are cut down to remove an equal amount from each side a total of 5" to 6" (127 to 152 mm) is the maximum that a blind can be cut down. Consequently, a larger number of stock widths must be maintained in inventory than would be needed if blinds could be trimmed at the locations closer to where the outermost ladders enter the headrail. For that reason there is a need for a headrail for venetian type blind and blinds containing a headrail that can be cut down very close to the outermost ladders.